Mining machine bit



o. PHlPPs MINING MACHINE BIT Y Filed April 23, 1945 Sept. 21, 1943.

' 2 Sheets-Sheet l H15 .TTORA/Ex Sept. 21, 1943. o. PHlPPs MININGMACHINE BIT 2 Sheets-Sheet 2 Filed April 23, 1943 /n/VE/vroz:

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Patented Sept. 21, 1943 MINING MACHINE Brr Orville Phipps, Denver,Colo., assignor to Central Mine Equipment Co., St. Louis, Mo., acorporation of Missouri Application -April 23. 1943, Serial No. 484,142

Claims.

This invention relates to mining machine bits; and has special referenceto a type of cutting bits sometimes called undercutting bits, which arefor attachment to the lugs of endless powerdriven cutter chains.

Objects of the invention are to provide an improved unitary or one-pieceAcutting bit comprising a body composed of an electric steel casting ordrop forging and including a shank to be received in the chain lugsocket, and a head integral with the shank and having alined shouldersat its front and rear sides for engaging against the outer wall of thechain lug at the front and rear sides of the socket into which the shankextends, and having a forwardly inclined wall extending from the frontshoulder toward the outer end of the head; to provide a very hardsynthetic metallic alloy insert in the form of a lcutting blade or pointlocated within a recess in the front side of the outer end of the headand `having its front surface in alinement with said inclined wall andhaving its side cutting edges tapering or converging outwardly towardthe outer end of the head and flush or in alinement with converging sideedges of the head and terminating at and intersecting the outer endcutting wall of said insert which has a lateral width or lengthapproximately equal to onehalf of the thickness of the head at theopposite end 'of said insert; and to provide a bit structure in whichthe stresses and strains to which the cutting point or end of the bit issubjected when in use are imparted to the' rear shoulder that engagesagainst the outer surface of the chain lug at the rear of the socketinto which the bit shank extends. l

Another object of the invention is to provide an improved unitary orone-piece metallic undercutting bit having the form and arrangementdeiined in the preceding paragraph and in which the metallic syntheticalloy insert possesses substantially the hardness of diamonds and iswelded or otherwise integrally attached to the head of the bit bodywithin the'recess provided for said insert and having its side and outerend walls alined with dat side and outer end walls of the head so that.when the end of the bit head becomes worn during use thereof, or whenthe insert becomes detached, dulled or damaged, it may be removed andthe said ilat side and outer end walls reformed by grinding and a newinsert welded to the head within .said recess in substitution for theone that had been removed, thus enlarging and extending the time duringwhich the bit may be used much longer than the time during which bits ofother constructionsmay be used.

Another object of the invention is to provide a metallic undercuttingbit adapted to be detachably secured to the lug of an endless chainhaving a novel type and form of cuttingblade integrally but detachablyand replaceably secured Within a recess in theouter end portion of thebit head and having three cutting edges of substantial length and widthalined with the adjacent nat walls of the blt head.

Other objects of the invention will be apparent from the followingdescription, reference being made to the annexed drawings, in which-Fig. l is a side elevation of a portion of an endless mining machinechain having my improved bit attached thereto, one of said lugs being insection.

Fig. 2 is a cross-sectional view through the bit I and a portion of thechain lug on the line 2-2 'of Fig. 1.

Fig. 3 is a sectional view of a chain lug similar to the sectionalviewof the lug shown in Fig. l, showing the bit in reversed position inthe lug for undercutting when the chain is moved in the oppositedirectionfrom the movement oi' the chain when the parts are arranged asin Fig. 1.

Fig. 4 is an enlarged front side elevation of the bit detached from thelug.

Fig. 5 is a rear elevation.

Fig. 6 is an outer end plan view of the bit.

Fig. 'I is a perspective view of the hard metallic synthetic alloyinsert having three relatively long and Vwide cutting edges, before saidinsert ls attached tothe bit body. y

Fig. 8 is a sectional view of a chain lug showing a bit of modifiedconstruction.

Fig. 9 is a sectional view on the line 9--9 o! Fig.`8.

Fig. 10 is an enlarged front side elevation of the bit of Fig. 8 apartfrom the chain.

Fig. 1l is a rear side elevation ofthe bit.

'As shown in the drawings, one speciiic form of my improved unitary orone-piece metallic cutting bit has a body composed of an electricsteelcasting and including a shank I, a head 2 integral with the shankand having a shoulder 3 at and extending across its front side at theunion of the shank and head, and a. shoulder 4 at and projectingstubstantially beyond the rear side of the shank at the union of thehead and shank. The shank I is arranged to extend into the socket 5 ofthe chain lug 6. The shoulders 3 and 4 are` relatively alined so thatboth engage against the outer wall of the chain lug at the front andrear sides of the socket 5 when the bit is properly mounted on the lug.The shank I has a thickness approximately equal to the width of thesocket 5 transversely of the lug, and has a width in the oppositedirection slightly less than the width of the socket in the plane of themovement of the chain, as indicated by the arrow 1 (Fig. 1), or asindicated by the arrow 8 (Fig. 3)

In order to attain its several advantages and objects, the head 2 ofthis bit is made of novel construction and form. It has a forwardlyinclined wall 9 extending from the front shoulder 3 toward the outer endof the head and terminating at the end wall I of a recess I I formed inthe front side of the outer end of the head. From the end wall I0 to thefiat outer end wall I2 of the head, two fiat walls I3 converge tointersection with said flat wall I2. The transverse width of the fiatwall I2 when seen from the front or rear of the bit is about one-half ofthe thickness of the head of the bit, more or less.

From the rear end of the flat outer end wall I2, the head of the bitincludes a symmetrically formed rounded rearwardly and inwardly inclinedend wall I4, which facilitates movement of the bit through the mineralcuttings when the chain is moved to provide such cuttings. The roundedend wall I4 extends to intersection with the end wall I5 of the rearshoulder 4.

A very hard synthetic metallic alloy insert constituting a cutting bladeor point I6 is tted in the recess II with its inner end seated on andagainst the end wall I0 of said recess, its outwardly converging sidewalls I1 even and in alinemcnt with the two flat walls I3. and its outerend wall I8 even and in alinement with the at outer end wall I2 of thebit head. The cutting blade I6 is integrally attached to the end of thebit by welding so as to dispense with the use of screws, clamps, orother equivalent fasteners. The front surface of the cutting blade i6 isin the same inclined plane with the wall 9 which inclines rearwardly andinwardly to the outer Wall of the lug 6. The sides of the head 2 areflat, and are parallel with each other from the shoulders 3 and 4 to thelines I9 extending from the end Wall I8 to the end wall I0 of the recessII and along the inner sides of the two fiat walls I3. The lines I9 areparallel with each other and with the outer and rear edge of the 'headdefined by the rounded end wall I4.

When the end of the head 2 dei'lned by the flat outer end wall I2becomes worn, and the cutting blade I6 becomes worn or damaged, the saidworn or damaged cutting blade may be detached from the head 2 bybreaking the weld by which said blade is attached to the head; and thehead 2 may be ground across the front to extend the length of the recessII that had been shortened by wearing away of the end of the head; andmay be ground at both sides to form two fiat side walls like theoriginal flat walls I3, and also ground to form a flat outer end walllike the original at outer end wall I2; and then a new or substitutecutting blade I6 may be welded in connection with the reshaped andreground bit head in substitution for the one that had become worn anddamaged and had been removed. This considerably extends the usefulnessof the bit for a longer period of time than the useful period of anyunitary bits with which I am familiar. The bits may thus be repaired atthe mines and the cost of operation correspondingly reduced, a facilitythat has lon been desired and sought.

The modified specific form of metallic cutting bit shown in Figs. 8 to1l, inclusive. has the shank 20 provided for the same purpose as theshank I, and the head 2I of greater transverse thickness than thetransverse thickness of the shank 20, thusI providing two side shoulders22 in alinement with each other and in allnement with the front shoulder23 and rear shoulder 24. All of the shoulders 22, 23 and 24 engageagainst the outer wall of the chain lug 6 when the shank 20 is extendedinto the socket 5 of the lug. The remaining structural features of thehead of this form of bit are the same as the structural features of thebit first described, are for the same purpose, and have the samereference numerals applied thereto in the drawings.

Either form of bit may be mounted in reverse position in the chain lug,as shown in Figs. 1 and 3, so that the clamping set screw 25 may engagethe rear side of the bit shank when the chain is moved in the directionof the arrow 1 (Fig. 1), or may engage the front side of the blt shankwhen the chain is moved in the direction of the arrow 8 (Fig. 3).

In both specific forms of the bit, the front or exposed corners of thecutting blade formed by intersection of the two elongated side walls I1and by intersection of the outer end Wall I8 with the front wall of thecutting blade, are the cutting edges of the blade and bit. The bit doesnot extend into the solid mineral; that is, the blt does not and is notintended to cut into the solid mineral deeper or to a further extentthan thelength of the cutting blade I6. Thus, the corners of the bithead formed by intersection of the flat side walls I3 with the inclinedwall 9 do not cut into the solid mineral through which the bit isoperated. The arrangement is such that the cutting blade I6 defines thedepth or thickness of the cutting and is long enough to perform theentire cutting operation; that is to say, such cutting operation may beperformed by said cutting blade only throughout the entire length of thecutting edges or corners formed by intersection of the side walls I1with the front wall of the blade.

When either specific form of the bit is equipped with a new cuttingblade in substitution for one that had been worn or damaged and detachedfrom the head, the relationship of the cutting blade with othercooperative features of the head is not undesirably affected or changedto any appreciable extent. 'I'he inclined rounded end wall I4, which isrearwardly beyond the nat outer end wall I2 and rearwardly beyond thetwo converging lat walls I3. does not become worn to any appreciableextent even though the end of the bit head defined by said end wall I2and the end I8 of the cutting blade I6, and the side walls I1 of theblade and the converging fiat walls I3 of the head, become worn to suchan extent that the length and width of the cutting blade aresubstantially reduced or lessened. 'I'hese structural features of thebit head are arranged and formed in such a manner that a new cuttingblade may be substituted for one that had become worn or damaged, or forone that had become accidentally detached, to restore the bit to a.condition for further and much longer use.

The synthetic metallic alloy insert I 6 is dened.

and known as tungsten-titanium carbide," corresponding to thechemicalformula WTiCz, produced by powder metallurgy. 'This alloy isfine grained and is crater resistant, having compression strength of690,000 pounds per square inch and a Rockwell hardness or 90.6. Theinsert is welded or crazed on the bit head. It cuts through the hardestminerals and is much less subject to wear than other cutting blades orbit heads with which I am familiar.

It is now known that this type of bit is practicable; may bemanufactured at quite low and permissible cost; may be used for muchlonger periods of time than other known unitary or onepiece bits; andappreciably lowers the cost of mine operation. These advantages andsavings have long been desired and unsuccessfully sought by otherexpedients. Heretofore, when the unitary or one-piece bits became worn,it was impossible to provide or equip them with hard cutting blades orto regrind them so as to extend their life very appreciably.

I claim:

1. In a mining machine metallic cutting bit having a shank forattachment to a chain lug, and a head integral with the outer end ofsaid shank beyond the lug, to which the shank is attached; alined frontand rear shoulders at the front and rear of the bit extending forwardlyand rearwardly beyond said shank at the union of the head shank forengaging against the outer wall of the chain lug, a front wall incliningforwardly from said front shoulder toward the outer end of the head, arecess in and across the entire front side of the outer end portion ofthe head outwardly beyond said front Wall, two iiat outwardly convergingside walls at the outer end portion of said head at the two sides of andextending the length of said recess, a flat outer end wall at the outerend of said head, and a cutting blade tted in said recess and having itsfront surface in alinement with said inclined wall and having two sidewalls and an nuter end wall alined with said i'lat side walls and iiatend wall of said head respectively.

2. In a mining machine metallic cutting bit having a shank for extensioninto a socket in a chain lug, and a head integral with the outer end ofsaid shank beyond the lug into which said shank extends; said headhaving a. recess in and across the entire front side of the outer endportion thereof, a front wall inclining forwardly from the plane ofunion of said shank and head to said recess, two at outwardly convergingside walls at the outer end portion of said head at the two sides of andextending the length of said recess and to the outer end of said head, aiiat outer end wall at the outer end of said head intersecting said flatside walls and the rear wall of said recess, and a cutting bladeintegrally attached to said head in said recess and having its frontsurface in alinement with said inclined wall and having itstwo sidewalls and its outer end wall alined with said flat side walls and saidiiat end wall of said head respectively.

3. In a mining machine metallic cutting bit having a shank for extensioninto a socket in a chain lug, and a head integral with the outer end `ofsaid shank beyond the lug into which said portion of said headintersecting said fiat outer end wall, said head having a recess in itsfront side extending the full length of said at side walls andterminating at said front wall, and a hard synthetic metallic alloycutting blade integrally attached to said head in said recess and havingits side walls and outer end Wall in the same plane with said flat sidewalls and said flat end Vwall of said head respectively.

4. In a .mining machine metallic cutting bit having a shank forextension into a socket in a chain lug, and a head integral with theouter end of said shank beyond the lug into which said shank extends,said head having a recess in the l front side of its outer end portion;a front wall inclining forwardly from the plane of union of said shankand said head to said recess, a at outer end wall-at the outer end ofsaid head intersecting the rear Wall of said recess and extendingapproximately parallel with the line o f union of y from the rear sidesof said flat side walls and said iiat end wall to the rear side of thehead, and a hard synthetic metallic alloy cutting blade integrallyunited with said head in said recess and having its side walls and outerend wall in the same plane with said flat side walls and said at endwall of said head respectively, and cutting edges at the intersection ofthe side walls and end wall of said cutting blade with the front wallthereof.

5. As an article of manufacture, a mining machine metallic cutting bithaving a head provided with a recess its'its front side extendinginwardly from its outer end, a flat outer end wall extending rearwardlyfrom said recess, a rear wall incliningvinwardly and rearwardly fromsaid fiat wall at the outer end of said head and having its sidesextending to the sides of the inner end of said recess, two flatoutwardly converging side walls at the outer end portion of said headintersecting said at outer end wall and extending to the inner end ofsaid recess, and a hard synthetic `metallic alloy cutting blade attachedto said head in said recess and having its outer end wall and side wallsin the same plane with said fiat end wall and said at side walls of saidhead respectively.

ORVILLE PHIPPS.

